Stoker



Patented Dec. 1, 1925, I

' UNITED STATES I 1,563,762 PATVIENT- OFFICE.

EDWIN LUNDGREN, OI FREDERICK, MARYLAND, ASSIGNOR '10 COMBUSTION EN-GINEERING- CORPORATION, OF YORK, N. Y., A CORPORATION OF-NEW YORK.

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Application filed October 16,1923. Serial No. 688,798.

To all whom it may. coniem nf Be it known-that I, Euwm LUNDGREN, acitizen of the United States, residing at Frederick, county ofFrederick, State of Maryland, have invented a certain new and usefulImprovement in Stokers, vof. which the following is a full, clear, andexact description.

My invention relates to furnaces and has special reference to furnacesfthe multiple retort underfeed stoker type;

' of. The underfeed An object of the invention is to provide a novel andimproved stoker of this type. Another object of the invention is toprovide novel and improved fuel supporting and air supplying means for astokerof this type.

Another object of the invention is to provide an underfeed stoker inwhich the air from the Wind box is evenly distributed to thefuel-thoughout the area of the underfeed grate section. l l

The several features of the invention,

whereby the above mentioned and other objects of the invention may beattained, will be clearly understood from the following description andaccompanying draw-- in s, in Whichigure 1 is a longitudinal sectionalview,- partly in elevation, of a portion of an underfeed stokerembodying the features of the invention in their preferred form;

Fig. 2 is a transverse sectional view, on an enlarged scale, taken onthe line 2 2 of Fig. 1 g

Fig. is asectional "view, on an enlarged scale, taken on the line 3-3 ofFig. 2; and Fig. 41 is a detail bottom plan view of one of the tuyereblocks employed in the stokcr. 4 The furnace illustrated in the drawingsis of the t pc of the one illustrated and described .in the patent toRiley No. 1,322,822, dated Nov. 25, 1919. As shown this furnacecomprises an underfeed grate 2, and an overl eed grate 4 at the reartheregrate comprises a plurality of downwardly and rearwardly inclinedretorts (3 arranged side by side i and spaced apart with the outer wallsof 10. The bottom walls 8 of the several retort-s form continuations ofthe bottom the fuel walls, respectively,

the furnace. The overfeed' grate is made up of a plurality of sectionsarranged side by side, each of which is associated with one of the sidewalls of one of thevretorts and these parts together with the row oftiiyere blocks supported on the side wall are adapted to be movedtogether as a unit.

back and forth in a substantially horizontal direction so as to effectthe feed of the fuel progressively .while in the course of combustion,and the discharge of the refuse of the fuel into the usual ash pitlocated at the rear of the overfeed rate. To enable said units to bethus moved back and forth, each overfeed grate section is mounted on ashoe 22 adapted to slide horizontally on a support 24, the lower or rearend of the associated retort side wall being pivotally connected at 26tothe shoe and its upper or forward end being suitably mounted forsliding movement. The means for actuating the several movable units,'asabove described, comprises links 28 connecting the forward ends of thewalls of each retort with the feeding plungers 16 associated with theretort. H

Except as hereinafter described, the parts above referred to may be andpreferably are the same as the corresponding parts of the stokerillustrated and described in said patent to Riley No. 1,322,822 to whichref- Y erence may be had for more complete description of the same.

In the embodiment of the present invention illustrated in the drawings atuyere structure comprising a row of tuyere blocks 30 is mounted on thebottom wall of each retort. These tuyere blocks are arranged one uponanother in overlapping relation and may be of a common construction,each having a depending hook-shaped lug 32 that extends through anopening 34 in the top Ill) wall of the block upon which it rests andhooks under the rear end wall of the opening, the depending hook-shapedlugiof the a wall. Each tuyere block is provided with arrangedsubstantially in the the usual top wall 38 and side wall :10 having itslower edge corrugated so as to form tu'yereopenings 42, the bottom wallof the retort being provided with a longitudinally extending opening 44for supplying air to thetuyere openings 42 of the blocks from the windbox of the furnace. The top surface of the uppermost tuyere block isplane of the bottom wall of the fuel hopper 12.

With this construction it will be apparent that during the operation ofthe stoker fuel will be fed by the plungers 16 from the hop pers 12 intothe upper ends of the fuel retorts, over the top surface of theuppermost tuyere block30 of each row, and down over these rows oftuyereblocks. Also this feeding operation causes the fuel to be forcedup over the tuyere blocks 18 on the side walls of the retorts, thereciprocation of the side walls of the retorts and the tuyere blocks 18carried thereby acting to uniformly feed the fuel downwardly'over thesetuyere blocks and also downwardly over the tuyere blocks 30. It will beapparent that the rows of tuyere blocks 30 not only constitute thebottoms of the retorts over which the fuel is fed to the tuyre blocks18, but also as they extend substantially the entire width of theretorts, and the top surface of the uppermost block 30 of each row issubstantially in the plane of the, bottom wall of its associated hopper12, they constitute active overfeed grate sections that cooperate withthe tu'yere structures 18 to evenly distribute air from the wind boxv tothe fuel throughout the entire width of the furnace. -Thus a uniformlyactive fuel burning surface is provided that extends the entire width ofthe fire box of the furnace, and is made up of a plurality of sectionsalter- As will be evident to those skilled in the art, my inventionpermits of variousmodifications without departing from the spiritthereof or the scope of the appended claims.

' What I claim is:

l. A furnace having, in combination, a downwardly and rearwardlyinclinedfuel retort having side walls longitudinally movable and adownwardly and rearwardly inclined bottom wall, tuyere structuresmounted on said side walls, means for recipro'cating said side wallslongitudinally and for feedingfuel into the forward end of the retort,and a row of tuyere blocks one upon the other in overlapping relationmounted on the inclined bottom wall of the retort spaced a distancebelow the top surfaces of said first mentioned tuyere structures andextending substantially the width of the retort.

2. A furnace having, in combination, a

downwardly and rearwardly inclined fuel retort having side wallslongitudinally movable, tuyere structures mounted on said side walls,means for reciprocating said side walls longitudinally and for feedingthe fuel into the forward end of the retort, and

a tuyere structure mounted on the inclined retort of substantially thewidth of and extending substantially bottom wall of the the length ofthe retort for supplying air to the fuel throughout substantially thearea of the retort.

3. A furnace having, downwardly. retort having able, tuyere structuresmounted on said side walls, means'for feeding the fuel into the forwardend of the retort comprising a hopper having its bottom wall formingsubstantially acontinuation of the bottom wall of the retort, means forreciprocating said side walls longitudinally and for feeding fuel intothe forward end of the retort, and a row of tuiyere blocks mounted onthe bot tom wall 0 the retort arranged one above the'other inoverlapping relation, spaced a distance below the top surface of saidfirst mentioned tuyere structures and extending substantially the widthof the retort, the top surface of the uppermost tuyere block in the rowbeing arranged substantially in the plane of the bottom wall of saidhopper.

4. A furnace having, in combination, a downwardly and rearwardlyinclined fuel retort having side walls longitudinally movable and abottom wall inclined downwardly and rearwardly, tuyere structuresmounted on said side walls, means for feed ing the fuel into the forwardend of the retort comprising a hopper having its bottom wall formingsubstantially a continuation of the bottom wall of the retort, and a rowof tuyere blocks mounted on the bottom wall of the retort arranged oneabove the other in overlapping relation, spaced a distance below the topsurface of said firstmentioned tuyere structures and extendingsubstantially from the lower end of the retort to a point so as toposition the top surface of the uppermost tuyere block substantially onthe level with said bottom wall of said hopper, said bottom wall of theretort in combination, a and rearwardly lnclmed fuel having an airsupplying opening, and the in- EDWIN LUNDGREN.

side walls longitudinally mov-

